Black holes , gravity.

Scientists say that in mathematical terms in singularity all the math breaks down and you get infinity. But how come this be if the black hole formed from a star that had huge but still limited amount of matter/fuel in it, and that limited amount just got highly compressed.
And if there even is a infinite thing in our universe and the universe itself I think shouldn't be infinite.
So my question is why the numbers show us otherwise?

Our knowledge of physics at scales similar to a black hole is severely limited.

This means at the scale of singularities, say around the order of Placnk scale, around 10-33 cm our models don't work so well...The 'infinity', described also as a divergence or a mathematical expression not well behaved, of models signals the likely breakdown of our approximations.

Staff: Mentor

Scientists say that in mathematical terms in singularity all the math breaks down and you get infinity. But how come this be if the black hole formed from a star that had huge but still limited amount of matter/fuel in it, and that limited amount just got highly compressed.
And if there even is a infinite thing in our universe and the universe itself I think shouldn't be infinite.
So my question is why the numbers show us otherwise?

The numbers predict an infinite density or zero volume. Density is mass divided by volume.